Sheet decurling apparatus



Jag. 11,1944.

L. O. HAYES SHEET DEGURLING APPARATUS Filed Oct. 24, 1941 Fig.1

2 Sheets-Sheet l -fifi 35 ig/7 33 53 59 1 6/ 44 I r v x {6 z a7- I0 40 L 26 Z6 5 53 59 I /0 j a INVENTOR. 45 w H44 L y/m Ohqyes ATTORNEYS Jan. 11, 1944. o, HAYES 2,339,070

SHEET DECURLING APPARATUS Filed 001:. 24, 1941 -2 Sheets-Sheet 2 INVENTOR. I Lynn 0. Hayes ATTORNEY-3 Patented Jan. 11, 1944 UNITED STATES V PATENT QFFICE SHEET DECURLING APPARATUS Lynn 0. Hayes, St. Louis, Mo., assignor to F. L. Smithe Machine Co.,'Inc., New York, N. 2., a corporation of New York Application October 24, 1941, Serial No. 418,293

(on. ss-sn 18 Claims.

This invention relates to decurlers suitable for taking the curl out of sheet material such as paper, and particularly for correcting the curling,

eliect of dried adhesive material located on one side of the paper. This is accomplished in general by drawing the sheet over a decurling edge engaging the convex side of the paper; and the decurling action is materially affected by the angle at which the sheet is drawn across such edge. The appropriate bend may be imparted to the sheet by passing it under a guide member located immediately in advance of thedecurlind edge; and may be varied by adiusting'the spacing oi the guide member and edge in a direction device eifective for .decurling a variety of types of stock.

A purpose of the invention is to providea decurler that is especially effective in decurling the gummed closure flaps of envelopes, and which is suitable for incorporation in continuous envelope iolding machines. Such flaps are customarily tapered, and the curling eifect of the dried gum is of course primarily restricted to the gummed area. which in the type of envelope most widely used is a strip extending along the tapered'margm of the flap, producing a V-shaped curled none that presents special decurling problems. In decurling envelope flaps the closure nap is initially bent over the decurling edge along a line adjacent and parallel to the Junction of thefiapwith the body, and is drawn across the edge with are especially effective for decurling envelope naps inthis mannenand I the device is constructed so that it may be incorporated in an envelope 'folding machine at any cate the device at a point where the side flapsof the blank have been folded in, but the bottom nap has not been gummed or folded.

Further obiects oi the include the II provision of a simple and strong construction which may be readily attached to standard types of sheet handling apparatus, such as envelope folding machines. I

Other objects and advantages of the invention will appear from the following description considered in connection with the accompanying drawings in which Fig. l is a plan view of a decurling device mounted on a standard type of envelope folding machine;

Fig. 2 is a transverse vertical section through the device on line 2-2 of Fig. 1; Fig. 3 is a similar but more diagrammatic view with the device in decurling position; and

Fig. 4 is a detail of an adjusting construction. The invention is disclosed in' its application to a machine for iolding envelope blanks having.

closure flaps the margins of which have been provided with gum in the usual manner. Such gum when dried tends to produce a substantial curl which prevents the folded envelopes from lying as flat as is desired. the inturned edges likewise tending to mark the body of the envelope. A machine of this type is disclosed in the patent to Winkler et al. No. 1,896,908.

Portions of such a machine, illustrated diagrammatically in Fig. 1, include a frame ll, driven rollers ll audit and cooperating pressure rollers I3 and arranged to convey an envelope blank I, having a bottom nap l8 and a closure flap ll, through a decurling device, the blank being supported by table Ii. Said table includes a feed section 20 extending to the bight between rollers ii and i3, intermediate sections 2| and 22 located between the two pairs of rollers, and discharge section :larranged to receive blanks discharged by rollers l2 and II, said table sections being arranged substantially in the same plane passing through the bights between the two sets of rollers.

' The decurling device is supported on posts 28 carried by frame ill, and consists of a stationary guide assembly anda movable decurling edge I unit. The guide assembly is mounted on supports is carried by posts 2| and includes guideand longitudinally of the direction of. blank travel; and in the preferred construction disclosed such mounting includes a yieldable support for thebar 21. This is advantageously accomplished by providing at each side of the path of the blanks an adjustable front stop against which the bar 21 is held by spring means, and a support 26 carrying a rearwardly extending arm 3| pivotally supported by pivot pin 32 and engaging guide bar 21. A suitable arrangement is provided for adjusting arm 3| about its pivot, the form disclosed comprising a post 33 on support 26 carrying an extension plate 34 projecting over arm 3|. Adjusting screw 35 threaded thr ugh plate 34 engages arm 3| and is restrained against accidental rotation caused by vibration or the like by coil spring 36 surrounding the shank of the screw. In the form illustrated bar 21 is not positively held by arm 3|, but is held yieldingly against the lower face of said arm, as by coil spring 31 seated in socket 38 in support 26 and bearing against the lower face of bar 21. In this specific form arm 31 is in turn pressed upwardly by bar 21, and bears against the lower end of screw 35 which serves as an adjusting stop for regulating the spacing of guide bar 21 and the decurling edge hereafter described, in a direction transverse to the path of the blanks.

A portion 'of each end of bar 21 is advantageously arranged to engage an arm 31 to limit endwise movement of the bar. Ihis is com veniently accomplished by constructing bar 21 in the form of a flat rectangular strip as shown, with its ends terminating adjacent arms 31 and extending above the lower faces of said arms. Pins 39 extending from the ends of bar 21 bearagainst the lower faces of arms 3| and are main tained in engagement therewith by springs 31.

A suitable arrangement is provided for adjusting bar 21 longitudinally of the direction of blank movement. In the form disclosed this includes a support plate 43 adjacent each end of the bar 21 against which the front face of the bar is normally held, plate 43 being provided with -an integral tail plate 44 (Fig. 4) having a slot 45 parallel to the direction of blank travel and slidably fitting a post 46 on support 26. Eocen tric 41 rotatable on post 46 bears against the rear face of support plate 43 and is held in adjusted position on the post by set screw 48.

An arrangement is provided for holding bar 21 in engagement with support plate 43. The dis closed construction for this purpose includes a plunger 50 slidable in bore in post 33, held in engagement with the rear face of-bar 21 by coil spring 52 in bore 5| bearing against pressure ad- J'usting screw 53 threaded into the rear end of said bore.

It will be understood that the described ar- II. are suitably held in position, as by support bars r 62 mounted on supports 26.

" upper face of table section 2| and forms a guide rangements for supporting guide bar 21 are duplicated at opposite ends of the bar outside of the path of the blanks l5.

The decurlin; edge unit comprises a decurling bar 55 extending transversely to and slightly below the. path of the blanks when in inopexatlve position, and movable upwardly to project across said path slightly beyond guide'b'ar 21 in the direction of blank travel when in operative posltion. The disclosed arrangement for moving bar 55 into and out of operative position includes a pair ofrock arms 56 connected to the ends of bar 55, arms 56 being supported by pivots 51 on posts 25. Each arm 56 carries a cam rol er 53 bearing against a face cam 59 fixed to the shaft 80 of roller ll, roller 58 being held on cam 59 throughout the cycleof operations by coil spring 3| extending from the end of arm ii to frame edge 64 at its intersection with the front face 65 of the guide bar. Decurling bar 55 is provided with a decurling edge 66 at the intersection of its rear face 61 with its top face 68, the latter being advantageously inclined at an acute angle to face 61 appropriate to avoid contact ofthe blank 15 with top face 68 after passing the decurling edge 66. v

With this arrangement the angle at which the blank is bent about edge 56 is determined by the angle between the portion of the blank extending from guide edge 64 to decurling edge 66 and the portion of the blank extending from the latter edge to the bight of rolls i2 and 14. Moreover, the paper will not ordinarily form an absolutely sharp angle when passing over edge 66, but will form a bend having a curvature which will depend upon the characteristics of the paper, and particularly its stiffness and thickness, as well as the tension upon the paper at this point. Such curvature, and the resulting decurling effect, will vary if the paper does not pass in a uniform plane to edge 66 from edge 64. Uniformity at the latter point is assured by extending table section 2| substantially to edge 64. Moreover, the sharpness of the bend about the latter edge will be influenced by the spacing between guide edge and the face of table section 21.

While the tension of spring 6| is normally suflicient to maintain rolle s 58 in engagement with cams 59, the tension of said springs may also be such that decurling bar 55 can yield downwardly under particularlyfexcessive strain to avoid rupture of the sheet in the manner already set forth. 7

I have described what I believe to be the best embodiments of my invention. I do'not wish, however, to be confined to the embodiments shown, but what I desire to cover by Letters Patent is set forth in the appended claims.

I claim:

1. Sheet decurling apparatus comprising a'decurling member and a guide member engaging opposite sides of a traveling sheet, arranged to bend the sheet across the decurling member, and an adjusting construction for varying the spacing of the decurling member and the guide member in the direction of sheet travel.

2. Sheet decurling apparatus comprising, in combination, means defining substantially a path of sheet travel, a decurling member and a guide member engaging opposite sides of a traveling sheet'arranged to bend the sheet across the decurling' member, and means yieldably maintaining said members in predetermined spaced relation longitudinally of thesheet path, including a stop engaged by one of the members and -a spring arranged to bias said member toward the other member and against the stop.

3. Sheet decurling apparatus as set forth in claim 2 in which the stop and spring act upon the guide member, said guide member being biased in the direction of sheet travel .against the stop.

4. Sheet dec'urling apparatus comprising a The intermediate table sections 21 and 22 12. Sheet decurling apparatus as set forth in claim in which the guide member and the sheet guide are relatively adjustable in a direction transverse to the sheet path.

13. Apparatus for decurling traveling sheets comprising a table structure, mechanism for advancing sheets successively including a pair of sheet advancing rolls and a pair of rolls arranged to feed sheets to the advancing rolls along the claim 4 in which the guide member support includes a stop and a spring device for yieldably biasing the guide member against the stop.

6. Sheet decurling apparatus as set forth in claim 4 including a device for adjusting the spacing of the sheet engaging portions of the guide member and decurling member transversely to the direction of sheet travel.

7. Sheet decurling'apparatus as set forth in claim 4 including a device for adjusting the spacing of the sheet engaging portions of the guide member and the decurling member transversely to the direction of sheet travel, said latter adjusting device comprising an adjustable stop and a spring device arranged to bias the guide member toward the stop.

8. Sheet decurling apparatus comprising a decurling member arranged to engage one side of a traveling sheet, a guide member in advance of the decurling member'arranged to engage the other side of the sheet and to bend the sheet across the decurling member, and a floating support for the guide member including a stop construction and a spring construction arranged to bias the guide bar against' the stop construction in the direction of sheet travel and also transversely to the direction of sheet travel.

9. Sheet decurling apparatus comprising sheet advancing mechanism, a decurling member at one side of the sheet path having a decurling edge formed by the intersection of two adjacent surfaces of the decurling member at an acute angle to one another, a guide member at the other side of the sheet path in advance of the decurling member, said members being spaced from said path in inoperative position, one of the members being movable transversely to the path and toward the other member lengthwise of the path curling member, and mechanism for shifting said movable member into and out of operative po-- sition, including a rocker arm to which said movable member is fixed and actuating mechanism for rocking the rocker arm. I

10. Apparatus for decurling traveling sheets comprising a decurling member operable to and from a position for engaging the convex. side of y the sheet, a stationary guide member engaging table structure, a sheet decurling device including a decurling member movable between spaced portions of the table structure into engagement with the lower face of a sheet, a stationary guide member having a lower face located above the table structure and adjacent thereto in advance of the decurling member, arranged to bend a sheet across the decurling member, and actuating mechanism for moving the decurling member upward into engagement with the trailing portion of a'sheet and across the plane of the lower face of the guide member after the sheet has been fed across the table structure to the advancing rolls. and released by the feed rolls.

14. An envelope forming machine comprising side flap folding mechanism, bottom flap gumming mechanism, bottom flap folding mechanism, a top flap folding mechanism, conveying mechaming mechanism, and a decurling device located between said pairs of rolls including a decurling member arranged to engage the convex side of g the closure flap, a guide member arranged to engage the concave side of the closure flap in advance of the decurling member to maintain said flap in bent position across the decurling member when in operative position, actuating mechanism for shifting said members into and out of operative position, and an'adjusting construction for varying the spacing of the guidemember and the decurling member in the direction of sheet travel. 1

15. Sheet decurling apparatus comprising registering decurling members on opposite sides of the plane of a traveling sheet, actuating mechanism for moving a decurling member into decurl-- ing position adjacent to and overlapping the other member, a support on which said other member is mounted in stationary position, and a device for adjusting said stationary member on the support in a direction longitudinal to the travel of the sheet, thereby varying the longitudinal spacing between the members in decurling position.

16. Sheet decurling apparatus comprising a stationary decurling member located at one side of the plane of a traveling sheet, a registering movable decurling member at the other side of said plane, actuating mechanism for shifting the movable member into decurling position adjacent to and overlapping thestationary member, and a device for adjusting the spacing of said members in decurling position in the direction oi." sheet travel.

LYNN O. HAYES. 

